Controlling device



W. F'. CLARK CONTROLLING DEVICE Filed June '7 NOV 25a @Zz/W,

Patented Nov. 25, 1924.

UNITED .STATES PATENT OFFICE.

VJARREN F. CLARK, OF CILEVELAND, OHIO, ASSIGNOR, BY MESNE vasuSIGNlViEN"J3S, TO

AUTOMATIC ELECTRIC HEATER COMPANY, OF WARREN, PENNSYLVANIA, A COR- A PORATION OF DELAWARE.

oonrnonzciiver DEVICE.

Application filed June 7,

vices (C), 0f which the following is a full,

clear, and exact description.

The present invention relates to a device for controlling an electric heating coil in accordancewith temperature conditions existilng in the device, being heated bythe coi Oneobject of the invention is to provide a device for the purpose which is very sensitiveso that it responds readily to tempera ture conditions. Y

A further object is to provide` a device for the purpose which upon repeated continuedaction undergoes no changeswhich would cause it to become inactive as is frequently the case with thermostats working upon the principle of expansion and contraction.

A further object is to providea construction in Awhich a -confined fluid creates a pressure condition in accordance with the degree to which lit is heatedand a pressure responsive contact operated'or moving device'which' is operated under -predetermined pressure conditions of the fluid. An additional object is to provide an electricallyv heated device with which there is associ- -ated a closed receptacle containing a fluid, which receptacle is suitably connected with a pressure responsive device, such as a Bourdon tube, which tube is operatively connected with a pair of electrical contacts which control the circuit of which the electrical heating element is -a part so that the current is supplied to the heating coil at such times as are necessary to maintain the device being heated by the coil at a predetermined temperature.

Generally speaking, the invention may be said to comprise the elements and the coinbinations thereof set forth in the accom panying claims. l

Reference shouldbe had to the accompanying drawings forming a part of this i919. serial No. 302,401..

specification in which Fig. 1 is a vertical section through an electrically lheated device showing theregulator; ig. 2 is an elevation withV portions in section showing the controlling' device; Fig. 3 is a diagram showing an electric circuit concluding the heating coil,v which is to be controlled.

Referring to the. drawings, 1 indicates a container which in the present instance is a pipelike section which at its upper end is threaded and adapted to receive a hollow table, which is indicated at 2. The interior of the member 1 communicated with the intcrior of the table. In the construction illustrated, the member 1 is intended to function as a steam generator and the steam lgenerated is supplied to the interior of the member 2 which keeps the member 2 in a predetermined heated condition, the memberQ serving as a hot plate and may be utilied in various manners.

Surrounding the member 1 is an electrical c'oil 3. This coil is imbedded in a body of heat insulating material 4, which serves not onlv as a support for the coil, but as before indicated, serves to prevent radiation of heat from-the electric coil 3 so that the heat of the coil is delivered to the member 1 and the water contained therein.

The lower end of the member 1 receives a cap 5 which has a central opening adapted to receive a threaded bushing 6, this bushing has a central opening. Within the member 1 there extends a closed container 7 which is adapted to` contain a fluid which when heat volatilizesl or Hvaporizes thereby creating a pressure condition within the member 7.

Communicating with the interior of the -container 7 is asmall tube 8, and surrounding the tube, 8 is another tube 9, which is secured. to the exterior of the receptacle 7 bushing 6.

4 The tube 9, as before stated, extends upon the outside of the tube 8, forming a protecting casing for the small v tube 8 which might ioo otherwisebecome damaged. The tube secured 'to a. nipplie 10 which is carried by a casing ll, which casing contains a Bourdon tube l2. The tube 9 is seaied a the end Where it connects with the nipple i so that the only communication between container 7 and the Bourdon tube is through the tube 8. The Bourdon tube.7 as is Well lrnoi'vn,

is hollow and'one end ot it is secured to of the present invention. A further description thereot is unnecessary. y

Associated With the .casing ll is another casing 11b Within which there is mounted a pair of contacts l5 and 16, one ot ,these contacts is mounted upon a resilient member 17 and cooperating with the resilient member 17 is a pin 18 which is carried by the tree end of the Bourdon tube, expansion of the Bourdon tube will therefore cause the pin to engage with a resilient member thereby moving the contacts apart.

The position ot the-contacts with respect to the pin may be varied by adjusting the position ot the contacts so as to require -more or less movement oi? the end of the Bourdon .tube in order to eHcct engagement of the resilient member by the pin and consequent separation of the contacts.

lAs shown in 3', the circuit which energizes the heating coil Lt is controlled by the contacts and when the contacts are in engagement, the circuit is closed so that the coil 3 is energized and vice versa, when the contacts are seperated the coil is not energized.

It We assume that the container l has a suitable quantity of Water therein and that the container and Water are being hea-ted by the electric coil 3, it will be very clear that the container 7 and its contents Will be subject to the heat conditions Within the. member l', this will cause the tiuid Within the container 7 to expand and exert a pressure condition which is communicated to the interior of the Bourdon tube, thereby ca using the tube to expand and ultimately to ett'ect relative movement between the contacts for the purpose of breaking the circuit Which supplies electric current at the coil 3 By adjusting the position of the contacts With respect to the Bourdon tube; determines the degree of movement which the Bourdon tube shall have before moving the contacts tarn controlledby crest-iure condition Within the .container therefore it tvill be apparent that `the position ot' the contacts may be so adjusted as to cause the energizing circuit tor the heating coil to be broken in accordance with any predetermined pressure condition Within the member l and it will of course be understood that the pressure is directly proportional tothe temperature.

From the 'foregoing it will be seen that the device may be adjusted so as to substantially maintain a constant ten'iperatureA condition Within the member l, the circuit ot the coil 3 being` broken when the predetermined temperature condition is reached or exceeded and the electric current again being supplied to the coil 3 when the temperature condition drops below the predetermined temperature. ln the present instance l have shown and described a particular construction which the. controlling device assumes, but l do not thereby Wish to limit myself except as defined in the claims.

Having described my invention, l claiml; In a. device ot the character described, a closed receptacle, a fluid contained therein, a Bourdon tube, means connecting the Bourdon tube with the interior ofthe receptacle, a pair of contacts normally having a lixed position with respect to cach other and one ot which is resiliently mounted, means carried by the Bourdon tube for moving one of said contacts with respect to the other.

2. In a device of the character described, a closed receptacle, a iuid within said receptacle, a casing, a Bourdon tube Within said casing, a tubular member connecting the said casing with the receptacle, a second tube Within the first mentioned tube for connecting the interior of' the receptacle With the Bourdon tube, a pair of contact members which normally occupy va fixed relation With respect to each other one of Which is resiliently mounted, means carried by the Bourdon tube t'or moving one of said contacts With respect to the other.

3. ln a device of the character described, the combination With a container, av receptacle within the container, a tubular member connected With the receptacle and extending upon the outside of the container, a bushing through which the said tubular member extends, a Bourdon tube, means connectng the Bourdon tube with the interior of the receptacle, a pair ot contacts, which contacts are connected With the moving coil, and means carried by the Bourdon tube for moving one of the contacts with respect to the other, one of said Icontacts being resiliently mounted.

4f. In a device of the character described,

a container, a receptacle Within the oontainer, a tube connected with the receptacle a closure member forthe container through which said tubular member' extends, a casing connected with the said tubular member`7 a Bourdon tube Within the Casing, means for connecting the tubular member with the interior of the receptacle, a pair of oon-` tacts connected with the heating coil and means Carried by the Bourdon tube -for lo vwith respeet to the moving means carried by the Bourdon tube.

n testimony whereof, l hereunto afx l5 my signature. l

WARREN F. CLARK. 

